Abdominal exerciser



FIG. 1 is a front right perspective view of an abdominal exerciser showing our new design therefor;

FIG. 2 is a rear left perspective view thereof;

FIG. 3 is a top perspective view thereof;

FIG. 4 is a right side perspective view thereof;

FIG. 5 is a front elevational view thereof;

FIG. 6 is a rear elevational view thereof; and,

FIG. 7 is a top plan view thereof. 

The ornamental design for an abdominal exerciser, as shown and described. 